Pure Storage (PSTG) 10-Q 7 Jun 17 2017 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Apr. 30, 2017	May 31, 2017
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Apr. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q1
Trading Symbol	PSTG
Entity Registrant Name	Pure Storage, Inc.
Entity Central Index Key	1,474,432
Current Fiscal Year End Date	--01-31
Entity Filer Category	Large Accelerated Filer
Class A
Entity Common Stock, Shares Outstanding		93,938,912
Class B
Entity Common Stock, Shares Outstanding		114,766,953

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Apr. 30, 2017	Jan. 31, 2017
Current assets:
Cash and cash equivalents	$ 168,757	$ 183,675
Marketable securities	367,218	362,986
Accounts receivable, net of allowance of $2,000 and $1,744 as of January 31, 2017 and April 30, 2017	132,134	168,978
Inventory	39,478	23,498
Deferred commissions, current	16,409	15,787
Prepaid expenses and other current assets	28,637	25,157
Total current assets	752,633	780,081
Property and equipment, net	82,293	81,695
Intangible assets, net	6,184	6,560
Deferred income taxes, non-current	795	844
Other assets, non-current	30,970	30,565
Total assets	872,875	899,745
Current liabilities:
Accounts payable	51,015	52,719
Accrued compensation and benefits	24,714	39,252
Accrued expenses and other liabilities	15,981	21,697
Deferred revenue, current	159,094	158,095
Liability related to early exercised stock options	1,064	1,362
Total current liabilities	251,868	273,125
Deferred revenue, non-current	152,431	145,031
Other liabilities, non-current	3,268	3,159
Total liabilities	407,567	421,315
Commitments and contingencies (Note 5)
Stockholders’ equity:
Preferred stock, par value of $0.0001 per share— 20,000 shares authorized as of January 31, 2017 and April 30, 2017; no shares issued and outstanding as of January 31, 2017 and April 30, 2017	0	0
Class A and Class B common stock, par value of $0.0001 per share— 2,250,000 (Class A 2,000,000, Class B 250,000) shares authorized as of January 31, 2017 and April 30, 2017; 204,364 (Class A 87,027, Class B 117,337) and 208,119 (Class A 93,271, Class B 114,848) shares issued and outstanding as of January 31, 2017 and April 30, 2017	21	20
Additional paid-in capital	1,330,586	1,281,452
Accumulated other comprehensive loss	(445)	(562)
Accumulated deficit	(864,854)	(802,480)
Total stockholders’ equity	465,308	478,430
Total liabilities and stockholders’ equity	$ 872,875	$ 899,745

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Apr. 30, 2017	Jan. 31, 2017
Accounts receivable, allowance	$ 1,744	$ 2,000
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value per share (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	2,250,000,000	2,250,000,000
Common stock, shares issued (in shares)	208,119,000	204,364,000
Common stock, shares outstanding (in shares)	208,119,000	204,364,000
Class A
Common stock, par value per share (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	2,000,000,000	2,000,000,000
Common stock, shares issued (in shares)	93,270,847	87,027,000
Common stock, shares outstanding (in shares)	93,270,847	87,027,000
Class B
Common stock, par value per share (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	250,000,000	250,000,000
Common stock, shares issued (in shares)	114,848,323	117,337,000
Common stock, shares outstanding (in shares)	114,848,323	117,337,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Apr. 30, 2017	Apr. 30, 2016
Revenue:
Product	$ 138,425	$ 111,738
Support	44,206	28,209
Total revenue	182,631	139,947
Cost of revenue:
Product	46,645	34,046
Support	16,903	12,934
Total cost of revenue	63,548	46,980
Gross profit	119,083	92,967
Operating expenses:
Research and development	65,428	52,938
Sales and marketing	96,964	83,098
General and administrative	20,096	21,581
Total operating expenses	182,488	157,617
Loss from operations	(63,405)	(64,650)
Other income (expense), net	1,995	1,282
Loss before provision for income taxes	(61,410)	(63,368)
Provision for income taxes	964	420
Net loss	$ (62,374)	$ (63,788)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.30)	$ (0.34)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted (in shares)	205,783	189,283

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2017	Apr. 30, 2016
Statement of Comprehensive Income [Abstract]
Net loss	$ (62,374)	$ (63,788)
Other comprehensive income:
Change in unrealized net gain on available-for-sale securities	117	807
Comprehensive loss	$ (62,257)	$ (62,981)

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2017	Apr. 30, 2016
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (62,374)	$ (63,788)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	14,825	10,432
Stock-based compensation expense	32,219	22,998
Other	451	182
Changes in operating assets and liabilities:
Accounts receivable, net	36,571	28,593
Inventory	(16,105)	(2,623)
Deferred commissions	(362)	4,141
Prepaid expenses and other current assets	(3,944)	(2,744)
Accounts payable	(3,982)	166
Accrued compensation and other liabilities	(19,998)	(11,017)
Deferred revenue	8,398	20,653
Net cash provided by (used in) operating activities	(14,301)	6,993
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of property and equipment	(12,769)	(24,376)
Purchases of marketable securities	(55,976)	(343,466)
Sales of marketable securities	5,384	23,327
Maturities of marketable securities	46,321	0
Net decrease in restricted cash	0	706
Net cash used in investing activities	(17,040)	(343,809)
CASH FLOWS FROM FINANCING ACTIVITIES
Net proceeds from exercise of stock options	2,257	3,091
Proceeds from issuance of common stock under employee stock purchase plan	14,166	15,079
Net cash provided by financing activities	16,423	18,170
Net decrease in cash and cash equivalents	(14,918)	(318,646)
Cash and cash equivalents, beginning of period	183,675	604,742
Cash and cash equivalents, end of period	168,757	286,096
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION
Cash paid for income taxes	790	1,323
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING INFORMATION
Property and equipment purchased but not yet paid	9,685	9,448
Vesting of early exercised stock options	$ 298	$ 176

Business Overview

Business Overview	3 Months Ended
	Apr. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business Overview	Business Overview Organization and Description of Business Pure Storage, Inc. (the Company, we, us, or other similar pronouns) was originally incorporated in the state of Delaware in October 2009 under the name OS76, Inc. In January 2010, we changed our name to Pure Storage, Inc. We are building a data platform that transforms business through a dramatic increase in performance and reduction in complexity and costs. We are headquartered in Mountain View, California and have wholly owned subsidiaries throughout the world.

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	3 Months Ended
	Apr. 30, 2017
Accounting Policies [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	Basis of Presentation and Summary of Significant Accounting Policies Principles of Consolidation The condensed consolidated financial statements include the accounts of the company and our wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. Unaudited Interim Consolidated Financial Information The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (U.S. GAAP) and applicable rules and regulations of the Securities and Exchange Commission (the SEC) regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. Therefore, these condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes included in our Annual Report on Form 10-K for the year ended January 31, 2017 . In the opinion of management, the accompanying unaudited condensed consolidated financial statements reflect all normal recurring adjustments necessary to present fairly the financial position, results of operations, comprehensive loss and cash flows for the interim periods, but are not necessarily indicative of the results of operations to be anticipated for the full fiscal year 2018 or any future period. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported and disclosed in the financial statements and accompanying notes. Actual results could differ from these estimates. Such estimates include, but are not limited to, the determination of best estimate of selling price included in multiple-element revenue arrangements, sales commissions, useful lives of intangible assets and property and equipment, fair values of stock-based awards, provision for income taxes, including related reserves, and contingent liabilities, among others. Management bases its estimates on historical experience and on various other assumptions which management believes to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Restricted Cash Restricted cash is comprised of cash collateral for a vendor credit card program and letters of credit related to our leases. As of both January 31, 2017 and April 30, 2017 , we had restricted cash of $12.7 million , which was included in other assets, non-current, in the condensed consolidated balance sheets. Marketable Securities We classify our marketable securities as available-for-sale at the time of purchase and reevaluate such classification at each balance sheet date. We may sell these securities at any time for use in current operations even if they have not yet reached maturity. As a result, we classify our securities, including those with maturities beyond twelve months, as current assets in the accompanying condensed consolidated balance sheets. We carry these securities at fair value and record unrealized gains and losses in other comprehensive income (loss), which is reflected as a component of stockholders’ equity. We evaluate our securities to assess whether those with unrealized loss positions are other than temporarily impaired. We consider impairments to be other than temporary if they are related to deterioration in credit risk or if it is likely we will sell the securities before the recovery of their cost basis. Realized gains and losses from the sale of marketable securities and declines in value deemed to be other than temporary are determined on the specific identification method. To date, there have been no declines in value deemed to be other than temporary in any of our securities. Realized gains and losses are reported in other income (expense), net, in the condensed consolidated statements of operations. Deferred Commissions Deferred commissions consist of direct and incremental costs paid to our sales force related to customer contracts. The deferred commission amounts are recoverable through the revenue streams that will be recognized under the related customer contracts. Direct sales commissions are deferred when earned and amortized over the same period that revenue is recognized from the related customer contract. Amortization of deferred commissions is included in sales and marketing expense in the condensed consolidated statements of operations. As of January 31, 2017 and April 30, 2017 , we recorded deferred commissions, current, of $15.8 million and $16.4 million , and deferred commissions, non-current, of $14.9 million and $14.7 million , in other assets, non-current, in the condensed consolidated balance sheets. We recognized sales commission expenses of $17.6 million and $20.5 million during the three months ended April 30, 2016 and 2017 , respectively. Recent Accounting Pronouncements Not Yet Adopted In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers (ASU 2014-09), requiring an entity to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. ASU 2014-09 will supersede nearly all existing revenue recognition guidance under U.S. GAAP when it becomes effective. In August 2015, the FASB issued ASU No. 2015-14, Revenue from Contracts with Customers , deferring the effective date for ASU 2014-09 by one year. The new standard will be effective for us beginning on February 1, 2018 which is the mandatory adoption date and we do not plan to early adopt. This standard may be adopted using either the full or modified retrospective methods. We are evaluating the impact of the new standard on our accounting policies, processes, and system requirements, and have assigned internal resources and engaged third party service providers to assist in our evaluation and system implementation. We have made and will continue to make investments in systems to enable timely and accurate reporting under the new standard. We are also evaluating the potential impact that the implementation of this standard will have on our consolidated financial statements. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (ASU 2016-02). ASU 2016-02 requires lessees to recognize all leases with terms in excess of one year on their balance sheet as a right-of-use asset and a lease liability at the commencement date. The new standard also simplifies the accounting for sale and leaseback transactions. The amendments in this update will be effective for us beginning on February 1, 2019 and must be adopted using a modified retrospective method for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. Early adoption is permitted. We are currently evaluating adoption methods and the impact of this standard on our consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13). ASU 2016-13 amends guidance on reporting credit losses for assets held at amortized cost basis and available-for-sale debt securities to require that credit losses on available-for-sale debt securities be presented as an allowance rather than as a write-down. The measurement of credit losses for newly recognized financial assets and subsequent changes in the allowance for credit losses are recorded in the statements of operations. The amendments in this update will be effective for us beginning on February 1, 2020 with early adoption permitted on or after February 1, 2019. We are currently evaluating the impact of this standard on our consolidated financial statements. In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash (ASU 2016-18), which requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. ASU 2016-18 will be effective for us beginning on February 1, 2018 and will be applied on a retrospective basis. Early adoption is permitted. We do not expect the adoption of this standard to have any material impact on our consolidated financial statements. In May 2017, the FASB issued ASU No 2017-09, Compensation—Stock Compensation (Topic 718) — Scope of Modification Accounting, to clarify when to account for a change to the terms or conditions of a share-based payment award as a modification. Under the new standard, modification is required only if the fair value, the vesting conditions, or the classification of an award as equity or liability changes as a result of the change in terms or conditions. ASU 2017-09 will be effective for us beginning February 1, 2018 and will be applied prospectively. Early adoption is permitted. We are currently evaluating the impact of this standard on our consolidated financial statements.

Financial Instruments

Financial Instruments	3 Months Ended
	Apr. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Financial Instruments	Financial Instruments Fair Value Measurements We measure our cash equivalents, marketable securities and restricted cash at fair value on a recurring basis. We define fair value as the exchange price that would be received from sale of an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. We measure our financial assets and liabilities at fair value at each reporting period using a fair value hierarchy which requires us to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. A financial instrument’s classification within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. Three levels of inputs may be used to measure fair value: ▪ Level I —Observable inputs are unadjusted quoted prices in active markets for identical assets or liabilities; ▪ Level II —Observable inputs are quoted prices for similar assets and liabilities in active markets or inputs other than quoted prices that are observable for the assets or liabilities, either directly or indirectly through market corroboration, for substantially the full term of the financial instruments; and ▪ Level III —Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. These inputs are based on our own assumptions used to measure assets and liabilities at fair value and require significant management judgment or estimation. We classify our cash equivalents, marketable securities and restricted cash within Level 1 or Level 2 because they are valued using either quoted market prices or inputs other than quoted prices which are directly or indirectly observable in the market, including readily-available pricing sources for the identical underlying security which may not be actively traded. Our fixed income available-for-sale securities consist of high quality, investment grade securities from diverse issuers. The valuation techniques used to measure the fair value of our marketable securities were derived from non-binding market consensus prices that are corroborated by observable market data or quoted market prices for similar instruments. Cash Equivalents, Marketable Securities and Restricted Cash The following tables summarize our cash equivalents, marketable securities and restricted cash by significant investment categories as of January 31, 2017 and April 30, 2017 (in thousands): As of January 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash Equivalents Marketable Securities Restricted Cash Level 1 Money market accounts $ — $ — $ — $ 12,734 $ — $ — $ 12,734 Level 2 U.S. government treasury notes 148,298 22 (289 ) 148,031 13,226 134,805 — U.S. government agencies 40,398 2 (159 ) 40,241 — 40,241 — Corporate debt securities 185,701 242 (379 ) 185,564 — 185,564 — Foreign government bonds 2,377 2 (3 ) 2,376 — 2,376 — Total $ 376,774 $ 268 $ (830 ) $ 388,946 $ 13,226 $ 362,986 $ 12,734 As of April 30, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash Equivalents Marketable Securities Restricted Cash Level 1 Money market accounts $ — $ — $ — $ 12,732 $ — $ — $ 12,732 Level 2 U.S. government treasury notes 144,028 26 (313 ) 143,741 6,324 137,417 — U.S. government agencies 41,576 1 (147 ) 41,430 — 41,430 — Corporate debt securities 186,005 295 (307 ) 185,993 — 185,993 — Foreign government bonds 2,378 2 (2 ) 2,378 — 2,378 — Total $ 373,987 $ 324 $ (769 ) $ 386,274 $ 6,324 $ 367,218 $ 12,732 The amortized cost and estimated fair value of our marketable securities are shown below by contractual maturity (in thousands): As of April 30, 2017 Amortized Cost Fair Value Due within one year $ 162,839 $ 162,757 Due in one to five years 204,824 204,461 Total $ 367,663 $ 367,218 Based on our evaluation of available evidence, we concluded that the gross unrealized losses on our marketable securities as of April 30, 2017 were temporary in nature. The following table presents gross unrealized losses and fair values for those investments that were in a continuous unrealized loss as of April 30, 2017 , aggregated by investment category (in thousands). Less than 12 months Greater than 12 months Total Fair Value Unrealized Loss Fair Unrealized Fair Unrealized U.S. government treasury notes $ 120,441 $ (313 ) $ — $ — $ 120,441 $ (313 ) U.S. government agencies 38,679 (147 ) — — 38,679 (147 ) Corporate debt securities 85,382 (301 ) 2,269 (6 ) 87,651 (307 ) Foreign government bonds 878 (2 ) — — 878 (2 ) Total $ 245,380 $ (763 ) $ 2,269 $ (6 ) $ 247,649 $ (769 ) Gross realized gains or losses on sale of marketable securities for the three months ended April 30, 2016 and 2017 were not significant.

Balance Sheet Components

Balance Sheet Components	3 Months Ended
	Apr. 30, 2017
Balance Sheet Components Disclosure [Abstract]
Balance Sheet Components	Balance Sheet Components Inventory Inventory consists of the following (in thousands): As of As of Raw materials $ 3,003 $ 10,865 Finished goods 20,495 28,613 Inventory $ 23,498 $ 39,478 Property and Equipment, Net Property and equipment, net, consists of the following (in thousands): As of As of Test equipment $ 105,955 $ 116,629 Computer equipment and software 54,521 57,453 Furniture and fixtures 4,494 4,691 Leasehold improvements 10,332 11,438 Total property and equipment 175,302 190,211 Less: accumulated depreciation and amortization (93,607 ) (107,918 ) Property and equipment, net $ 81,695 $ 82,293 Depreciation and amortization expense was $10.1 million and $14.4 million for the three months ended April 30, 2016 and 2017 . Intangible Assets, Net Intangible assets, net, consist of the following (in thousands): As of As of Technology patents $ 10,125 $ 10,125 Accumulated amortization (3,565 ) (3,941 ) Intangible assets, net $ 6,560 $ 6,184 Intangible assets amortization expense was $326,000 and $376,000 for the three months ended April 30, 2016 and 2017 . The weighted-average remaining useful life of technology patents is 4.1 years. Due to the defensive nature of these patents, the amortization is included in general and administrative expenses in the condensed consolidated statements of operations. As of April 30, 2017 , expected amortization expense for intangible assets for each of the next five years is as follows (in thousands): Years Ending January 31, Estimated Future Amortization Expense Remainder of 2018 $ 1,128 2019 1,504 2020 1,504 2021 1,504 2022 544 Total $ 6,184 Accrued Expenses and Other Liabilities Accrued expenses and other liabilities consist of the following (in thousands): As of January 31, 2017 As of April 30, 2017 Sales and use tax payable $ 540 $ 292 Accrued professional fees 1,765 1,018 Accrued marketing 6,718 5,041 Accrued travel and entertainment expenses 2,235 3,015 Income tax payable 1,135 1,271 Other accrued liabilities 9,304 5,344 Total accrued expenses and other liabilities $ 21,697 $ 15,981

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Apr. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Operating Leases During the three months ended April 30, 2017, we extended the lease term of an existing office facility with total additional lease obligations of approximately $2.0 million with the lease expiring through March 2019. Letters of Credit As of January 31, 2017 and April 30, 2017 , we had outstanding letters of credit in the aggregate amount of $7.7 million , in connection with our facility leases. The letters of credit are collateralized by restricted cash in the same amount and mature at various dates through June 2024. Legal Matters On September 1, 2016, a purported securities class action entitled Ramsay v. Pure Storage, Inc., et al. was filed in the Superior Court of the State of California (San Mateo County) against us and certain of our officers, directors, investors and underwriters for our initial public offering (IPO), asserting claims under sections 11, 12 and 15 of the Securities Act on behalf of a purported class consisting of purchasers of our common stock pursuant or traceable to our initial public offering, and seeking unspecified compensatory damages and other relief. Substantially identical lawsuits were subsequently filed in the same court, bringing the same claims against the same defendants, captioned Peter Galanis v. Pure Storage, Inc., et al. (filed September 14, 2016), Curtis Wilson v. Pure Storage, Inc., et al. (filed September 15, 2016), Loren Moe v. Pure Storage, Inc., et al. (filed September 23, 2016), and Mason Delahooke and Mahsa Shirazikia v. Pure Storage, Inc., et al. (filed October 5, 2016). On October 27, 2016, the aforementioned actions were consolidated under the caption In re Pure Storage, Inc. Shareholder Litigation . On December 13, 2016, the plaintiffs filed a consolidated complaint. On January 26, 2017, the defendants filed a demurrer (motion to dismiss) to the consolidated complaint on the grounds that the plaintiffs failed to state a claim under the Securities Act. On April 4, 2017, the court sustained the demurrer as to all claims with leave to amend. On May 15, 2017, the plaintiffs filed an amended complaint, again asserting claims under sections 11, 12 and 15 of the Securities Act against us and certain of our officers, directors and underwriters for our IPO. On May 26, 2017 the defendants filed a demurrer (motion to dismiss) to the amended complaint on the grounds that the plaintiffs failed to state a claim under the Securities Act. The second demurrer is scheduled to be heard on July 6, 2017. We believe there is no merit to the allegations and intend to defend ourselves vigorously. From time to time, we have become involved in claims and other legal matters arising in the normal course of business. We investigate these claims as they arise. Although claims are inherently unpredictable, we currently are not aware of any matters that may have a material adverse effect on our business, financial position, results of operations or cash flows. Accordingly, we have not recorded any loss contingency on our consolidated balance sheet as of April 30, 2017 . Indemnification Our arrangements generally include certain provisions for indemnifying customers against liabilities if our products or services infringe a third party’s intellectual property rights. Other guarantees or indemnification arrangements include guarantees of product and service performance and standby letters of credit for lease facilities. It is not possible to determine the maximum potential amount under these indemnification obligations due to the limited history of prior indemnification claims and the unique facts and circumstances involved in each particular agreement. To date, we have not incurred any material costs as a result of such obligations and have not accrued any liabilities related to such obligations in the consolidated financial statements. In addition, we indemnify our officers, directors and certain key employees while they are serving in good faith in their respective capacities. To date, there have been no claims under any indemnification provisions.

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Apr. 30, 2017
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity Preferred Stock We have 20,000,000 authorized shares of undesignated preferred stock, the rights, preferences and privileges of which may be designated from time to time by our board of directors. As of April 30, 2017 , there were no shares of preferred stock issued or outstanding. Class A and Class B Common Stock We have two classes of authorized common stock, Class A common stock and Class B common stock. As of April 30, 2017 , we had 2,000,000,000 shares of Class A common stock authorized with a par value of $0.0001 per share and 250,000,000 shares of Class B common stock authorized with a par value of $0.0001 per share. As of April 30, 2017 , 93,270,847 shares of Class A common stock were issued and outstanding and 114,848,323 shares of Class B common stock were issued and outstanding.

Equity Incentive Plans

Equity Incentive Plans	3 Months Ended
	Apr. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Equity Incentive Plans	Equity Incentive Plans Equity Incentive Plans We maintain two equity incentive plans: the 2009 Equity Incentive Plan (our 2009 Plan) and the 2015 Equity Incentive Plan (our 2015 Plan). In August 2015, our board of directors adopted, and in September 2015 our stockholders approved, the 2015 Plan, which became effective in connection with our IPO and serves as the successor to our 2009 Plan. Our 2015 Plan provides for grants of incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance stock awards, performance cash awards, and other forms of stock awards to our employees, directors and consultants. We ceased grants of new awards under our 2009 Plan after the effective date of our 2015 Plan, and no new grants will be made from our 2009 Plan. Outstanding awards granted under our 2009 Plan will remain subject to the terms of our 2009 Plan and applicable award agreements, until such outstanding awards that are stock options are exercised, terminated or expired by their terms. We initially reserved 27,000,000 shares of our Class A common stock for issuance under our 2015 Plan. The number of shares reserved for issuance under our 2015 Plan increases automatically on the first day of February of each year through 2025, in an amount equal to 5% of the total number of shares of our capital stock outstanding as of the immediately preceding January 31. The exercise price of stock options will generally not be less than 100% of the fair market value of our common stock on the date of grant, as determined by our board of directors. Our equity awards generally vest over a two to four year period and expire no later than ten years from the date of grant. 2015 Employee Stock Purchase Plan In August 2015, our board of directors adopted and our stockholders approved, the 2015 Employee Stock Purchase Plan (2015 ESPP), which became effective in connection with our IPO. A total of 3,500,000 shares of Class A common stock was initially reserved for issuance under the 2015 ESPP. The number of shares reserved for issuance under our 2015 ESPP increases automatically on the first day of February of each year through 2025, in an amount equal to the lesser of (i) 1% of the total number of shares of our capital stock outstanding as of the immediately preceding January 31, and (ii) 3,500,000 shares of Class A common stock. The 2015 ESPP allows eligible employees to purchase shares of our Class A common stock at a discount through payroll deductions (or other payroll contributions) of up to 30% of their eligible compensation, subject to a cap of 3,000 shares on any purchase date or $25,000 in any calendar year (as determined under applicable tax rules). The 2015 ESPP provides for 24 month offering periods beginning March 16th and September 16th of each year, and each offering period consists of four six -month purchase periods, subject to a reset provision. If the closing stock price on the offering date of a new offering falls below the closing stock price on the offering date of an ongoing offering, the ongoing offering would terminate immediately following the purchase of ESPP shares on the purchase date immediately preceding the new offering and participants in the terminated ongoing offering would automatically be enrolled in the new offering (ESPP reset). On each purchase date, eligible employees will purchase our Class A common stock at a price per share equal to 85% of the lesser of the fair market value of our Class A common stock (1) on the first trading day of the applicable offering period or (2) the purchase date. Our closing stock price on the new offering date of March 16, 2017 was lower than the closing stock prices for both the offerings that started on March 16, 2016 and September 16, 2016, which triggered an ESPP reset for those offerings. The ESPP reset resulted in a modification charge of approximately $9.0 million , which is being recognized over the new 24 -month offering period ending on March 15, 2019. In addition, the original remaining unamortized stock-based compensation expense for each of the offerings is being recognized over the same 24 -month offering period ending on March 15, 2019. We recognized stock-based compensation related to our 2015 ESPP of $4.2 million and $4.1 million during the three months ended April 30, 2016 and 2017 . As of April 30, 2017 , there was $27.9 million of unrecognized stock-based compensation expense related to our 2015 ESPP which is expected to be recognized over a weighted-average period of approximately 1.9 years . Stock Options A summary of stock option activity under our equity incentive plans and related information is as follows: Options Outstanding Number of Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life (In Years) Aggregate Intrinsic Value (in thousands) Balance as of January 31, 2017 56,840,189 $ 7.15 7.0 $ 315,502 Options granted — — Options exercised (1,340,121 ) 1.84 Options forfeited/cancelled (605,324 ) 12.74 Balance as of April 30, 2017 54,894,744 $ 7.22 6.7 $ 273,338 Vested and exercisable as of April 30, 2017 30,739,000 $ 4.45 6.0 $ 208,957 The aggregate intrinsic value of options vested and exercisable as of April 30, 2017 is calculated based on the difference between the exercise price and the closing price of $10.61 of our Class A common stock on April 28, 2017. As of April 30, 2017 , total unrecognized employee compensation cost related to outstanding options was $115.6 million , which is expected to be recognized over a weighted-average period of approximately 2.7 years . Restricted Stock Units A summary of the restricted stock unit activity under our 2015 Plan and related information is as follows: Number of Restricted Stock Units Outstanding Weighted- Average Grant Date Fair Value Aggregate Unvested Balance as of January 31, 2017 8,783,024 $ 13.06 $ 99,863 Granted 8,014,950 10.19 — Vested (794,543 ) 10.38 — Forfeited (376,522 ) 12.18 — Unvested Balance as of April 30, 2017 15,626,909 $ 11.74 $ 165,802 As of April 30, 2017 , total unrecognized employee compensation cost related to unvested restricted stock units was $165.3 million , which is expected to be recognized over a weighted-average period of approximately 2.6 years . During the three months ended April 30, 2017 , we granted 827,000 (target number of units) performance stock units with both performance condition and service vesting conditions payable in common shares from 0% to 150% of the target number granted, contingent upon the degree to which the performance condition is met. Management determined it is probable that the performance condition will be satisfied and accordingly, we began recognizing stock-based compensation expense during the three months ended April 30, 2017. Stock-based compensation expense was $468,000 for the three months ended April 30, 2017 . Stock-Based Compensation Expense The following table summarizes the components of stock-based compensation expense recognized in the condensed consolidated statements of operations (in thousands): Three Months Ended 2016 2017 Cost of revenue—product $ 106 $ 397 Cost of revenue—support 1,092 1,774 Research and development 11,658 15,588 Sales and marketing 7,519 10,626 General and administrative 2,623 3,834 Total stock-based compensation expense $ 22,998 $ 32,219

Net Loss per Share Attributable

Net Loss per Share Attributable to Common Stockholders	3 Months Ended
	Apr. 30, 2017
Earnings Per Share [Abstract]
Net Loss per Share Attributable to Common Stockholders	Net Loss per Share Attributable to Common Stockholders Basic and diluted net loss per share attributable to common stockholders is presented in conformity with the two-class method required for participating securities. Basic net loss per share attributable to common stockholders is computed by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period, less shares subject to repurchase. Diluted net loss per share attributable to common stockholders is computed by giving effect to all potential dilutive common stock equivalents outstanding for the period. For purposes of this calculation, stock options, unvested restricted stock awards, repurchasable shares from early exercised stock options, and shares subject to ESPP withholding are considered to be common stock equivalents but have been excluded from the calculation of diluted net loss per share attributable to common stockholders as their effect is anti-dilutive. The rights, including the liquidation and dividend rights, of the holders of our Class A and Class B common stock are identical, except with respect to voting. As the liquidation and dividend rights are identical, the undistributed earnings are allocated on a proportionate basis and the resulting net loss per share attributed to common stockholders will, therefore, be the same for both Class A and Class B common stock on an individual or combined basis. We did not present dilutive net loss per share on an if-converted basis because the impact was not dilutive. The following table sets forth the computation of basic and diluted net loss per share attributable to common stockholders (in thousands, except per share data): Three Months Ended 2016 2017 Net loss $ (63,788 ) $ (62,374 ) Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted 189,283 205,783 Net loss per share attributable to common stockholders, basic and diluted $ (0.34 ) $ (0.30 ) The following weighted-average outstanding shares of common stock equivalents were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods presented because including them would have been anti-dilutive (in thousands): Three Months Ended 2016 2017 Stock options to purchase common stock 68,407 55,895 Restricted stock units 1,375 11,722 Early exercised stock options 2,666 390 Employee stock purchase plan 364 336 Total 72,812 68,343

Income Taxes

Income Taxes	3 Months Ended
	Apr. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Our provision for income taxes was primarily due to taxes on international operations and state income taxes. The difference between the provision for income taxes that would be derived by applying the statutory rate to our loss before income taxes and the provision for income taxes recorded was primarily attributable to changes in our valuation allowance, non-deductible stock-based compensation expense and the tax rate differential between the U.S. and foreign countries. As of April 30, 2017 , there were no material changes to either the nature or the amounts of the uncertain tax positions previously determined for the year ended January 31, 2017 .

Segment Information

Segment Information	3 Months Ended
	Apr. 30, 2017
Segment Reporting [Abstract]
Segment Information	Segment Information Our chief operating decision maker is a group which is comprised of our Chief Executive Officer, our Chief Financial Officer, and our President. This group reviews financial information presented on a consolidated basis for purposes of allocating resources and evaluating financial performance. We have one business activity and there are no segment managers who are held accountable for operations or operating results. Accordingly, we have a single reportable segment. The following table sets forth revenue by geographic area based on the billing address of our customers (in thousands): Three Months Ended 2016 2017 United States $ 111,227 $ 146,494 Rest of the world 28,720 36,137 Total revenue $ 139,947 $ 182,631 Long-lived assets by geographic area are summarized as follows (in thousands): As of As of United States $ 78,692 $ 79,491 Rest of the world 3,003 2,802 Total long-lived assets $ 81,695 $ 82,293

Basis of Presentation and Sum17

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Apr. 30, 2017
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The condensed consolidated financial statements include the accounts of the company and our wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.
Unaudited Interim Consolidated Financial Information	Unaudited Interim Consolidated Financial Information The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (U.S. GAAP) and applicable rules and regulations of the Securities and Exchange Commission (the SEC) regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. Therefore, these condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes included in our Annual Report on Form 10-K for the year ended January 31, 2017 . In the opinion of management, the accompanying unaudited condensed consolidated financial statements reflect all normal recurring adjustments necessary to present fairly the financial position, results of operations, comprehensive loss and cash flows for the interim periods, but are not necessarily indicative of the results of operations to be anticipated for the full fiscal year 2018 or any future period.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported and disclosed in the financial statements and accompanying notes. Actual results could differ from these estimates. Such estimates include, but are not limited to, the determination of best estimate of selling price included in multiple-element revenue arrangements, sales commissions, useful lives of intangible assets and property and equipment, fair values of stock-based awards, provision for income taxes, including related reserves, and contingent liabilities, among others. Management bases its estimates on historical experience and on various other assumptions which management believes to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities.
Restricted Cash	Restricted Cash Restricted cash is comprised of cash collateral for a vendor credit card program and letters of credit related to our leases.
Marketable Securities	Marketable Securities We classify our marketable securities as available-for-sale at the time of purchase and reevaluate such classification at each balance sheet date. We may sell these securities at any time for use in current operations even if they have not yet reached maturity. As a result, we classify our securities, including those with maturities beyond twelve months, as current assets in the accompanying condensed consolidated balance sheets. We carry these securities at fair value and record unrealized gains and losses in other comprehensive income (loss), which is reflected as a component of stockholders’ equity. We evaluate our securities to assess whether those with unrealized loss positions are other than temporarily impaired. We consider impairments to be other than temporary if they are related to deterioration in credit risk or if it is likely we will sell the securities before the recovery of their cost basis. Realized gains and losses from the sale of marketable securities and declines in value deemed to be other than temporary are determined on the specific identification method. To date, there have been no declines in value deemed to be other than temporary in any of our securities. Realized gains and losses are reported in other income (expense), net, in the condensed consolidated statements of operations.
Deferred Commissions	Deferred Commissions Deferred commissions consist of direct and incremental costs paid to our sales force related to customer contracts. The deferred commission amounts are recoverable through the revenue streams that will be recognized under the related customer contracts. Direct sales commissions are deferred when earned and amortized over the same period that revenue is recognized from the related customer contract. Amortization of deferred commissions is included in sales and marketing expense in the condensed consolidated statements of operations.
Recently Adopted Accounting Standard and Recent Accounting Pronouncements Not Yet Adopted	Recent Accounting Pronouncements Not Yet Adopted In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers (ASU 2014-09), requiring an entity to recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. ASU 2014-09 will supersede nearly all existing revenue recognition guidance under U.S. GAAP when it becomes effective. In August 2015, the FASB issued ASU No. 2015-14, Revenue from Contracts with Customers , deferring the effective date for ASU 2014-09 by one year. The new standard will be effective for us beginning on February 1, 2018 which is the mandatory adoption date and we do not plan to early adopt. This standard may be adopted using either the full or modified retrospective methods. We are evaluating the impact of the new standard on our accounting policies, processes, and system requirements, and have assigned internal resources and engaged third party service providers to assist in our evaluation and system implementation. We have made and will continue to make investments in systems to enable timely and accurate reporting under the new standard. We are also evaluating the potential impact that the implementation of this standard will have on our consolidated financial statements. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) (ASU 2016-02). ASU 2016-02 requires lessees to recognize all leases with terms in excess of one year on their balance sheet as a right-of-use asset and a lease liability at the commencement date. The new standard also simplifies the accounting for sale and leaseback transactions. The amendments in this update will be effective for us beginning on February 1, 2019 and must be adopted using a modified retrospective method for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. Early adoption is permitted. We are currently evaluating adoption methods and the impact of this standard on our consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (ASU 2016-13). ASU 2016-13 amends guidance on reporting credit losses for assets held at amortized cost basis and available-for-sale debt securities to require that credit losses on available-for-sale debt securities be presented as an allowance rather than as a write-down. The measurement of credit losses for newly recognized financial assets and subsequent changes in the allowance for credit losses are recorded in the statements of operations. The amendments in this update will be effective for us beginning on February 1, 2020 with early adoption permitted on or after February 1, 2019. We are currently evaluating the impact of this standard on our consolidated financial statements. In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash (ASU 2016-18), which requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Therefore, amounts generally described as restricted cash and restricted cash equivalents should be included with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. ASU 2016-18 will be effective for us beginning on February 1, 2018 and will be applied on a retrospective basis. Early adoption is permitted. We do not expect the adoption of this standard to have any material impact on our consolidated financial statements. In May 2017, the FASB issued ASU No 2017-09, Compensation—Stock Compensation (Topic 718) — Scope of Modification Accounting, to clarify when to account for a change to the terms or conditions of a share-based payment award as a modification. Under the new standard, modification is required only if the fair value, the vesting conditions, or the classification of an award as equity or liability changes as a result of the change in terms or conditions. ASU 2017-09 will be effective for us beginning February 1, 2018 and will be applied prospectively. Early adoption is permitted. We are currently evaluating the impact of this standard on our consolidated financial statements.

Financial Instruments (Tables)

Financial Instruments (Tables)	3 Months Ended
	Apr. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Summary of Cash Equivalents, Marketable Securities and Restricted Cash by Significant Investment Categories	The following tables summarize our cash equivalents, marketable securities and restricted cash by significant investment categories as of January 31, 2017 and April 30, 2017 (in thousands): As of January 31, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash Equivalents Marketable Securities Restricted Cash Level 1 Money market accounts $ — $ — $ — $ 12,734 $ — $ — $ 12,734 Level 2 U.S. government treasury notes 148,298 22 (289 ) 148,031 13,226 134,805 — U.S. government agencies 40,398 2 (159 ) 40,241 — 40,241 — Corporate debt securities 185,701 242 (379 ) 185,564 — 185,564 — Foreign government bonds 2,377 2 (3 ) 2,376 — 2,376 — Total $ 376,774 $ 268 $ (830 ) $ 388,946 $ 13,226 $ 362,986 $ 12,734 As of April 30, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash Equivalents Marketable Securities Restricted Cash Level 1 Money market accounts $ — $ — $ — $ 12,732 $ — $ — $ 12,732 Level 2 U.S. government treasury notes 144,028 26 (313 ) 143,741 6,324 137,417 — U.S. government agencies 41,576 1 (147 ) 41,430 — 41,430 — Corporate debt securities 186,005 295 (307 ) 185,993 — 185,993 — Foreign government bonds 2,378 2 (2 ) 2,378 — 2,378 — Total $ 373,987 $ 324 $ (769 ) $ 386,274 $ 6,324 $ 367,218 $ 12,732
Schedule of Amortized Cost and Estimated Fair Value of Marketable Securities by Contractual Maturity	The amortized cost and estimated fair value of our marketable securities are shown below by contractual maturity (in thousands): As of April 30, 2017 Amortized Cost Fair Value Due within one year $ 162,839 $ 162,757 Due in one to five years 204,824 204,461 Total $ 367,663 $ 367,218
Schedule of Gross Unrealized Losses and Fair Values for Investments that were in Continuous Unrealized Loss Position for Less Than 12 Months, Aggregated by Investments Category	The following table presents gross unrealized losses and fair values for those investments that were in a continuous unrealized loss as of April 30, 2017 , aggregated by investment category (in thousands). Less than 12 months Greater than 12 months Total Fair Value Unrealized Loss Fair Unrealized Fair Unrealized U.S. government treasury notes $ 120,441 $ (313 ) $ — $ — $ 120,441 $ (313 ) U.S. government agencies 38,679 (147 ) — — 38,679 (147 ) Corporate debt securities 85,382 (301 ) 2,269 (6 ) 87,651 (307 ) Foreign government bonds 878 (2 ) — — 878 (2 ) Total $ 245,380 $ (763 ) $ 2,269 $ (6 ) $ 247,649 $ (769 )

Balance Sheet Components (Table

Balance Sheet Components (Tables)	3 Months Ended
	Apr. 30, 2017
Balance Sheet Components Disclosure [Abstract]
Schedule of Inventory	Inventory consists of the following (in thousands): As of As of Raw materials $ 3,003 $ 10,865 Finished goods 20,495 28,613 Inventory $ 23,498 $ 39,478
Schedule of Property and Equipment, Net	Property and equipment, net, consists of the following (in thousands): As of As of Test equipment $ 105,955 $ 116,629 Computer equipment and software 54,521 57,453 Furniture and fixtures 4,494 4,691 Leasehold improvements 10,332 11,438 Total property and equipment 175,302 190,211 Less: accumulated depreciation and amortization (93,607 ) (107,918 ) Property and equipment, net $ 81,695 $ 82,293
Schedule of Intangible Assets, Net	Intangible assets, net, consist of the following (in thousands): As of As of Technology patents $ 10,125 $ 10,125 Accumulated amortization (3,565 ) (3,941 ) Intangible assets, net $ 6,560 $ 6,184
Schedule of Expected Amortization Expenses for Intangible Assets	As of April 30, 2017 , expected amortization expense for intangible assets for each of the next five years is as follows (in thousands): Years Ending January 31, Estimated Future Amortization Expense Remainder of 2018 $ 1,128 2019 1,504 2020 1,504 2021 1,504 2022 544 Total $ 6,184
Schedule of Accrued Expenses and Other Liabilities	Accrued expenses and other liabilities consist of the following (in thousands): As of January 31, 2017 As of April 30, 2017 Sales and use tax payable $ 540 $ 292 Accrued professional fees 1,765 1,018 Accrued marketing 6,718 5,041 Accrued travel and entertainment expenses 2,235 3,015 Income tax payable 1,135 1,271 Other accrued liabilities 9,304 5,344 Total accrued expenses and other liabilities $ 21,697 $ 15,981

Equity Incentive Plans (Tables)

Equity Incentive Plans (Tables)	3 Months Ended
	Apr. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Option Activity Under Equity Incentive Plans and Related Information	A summary of stock option activity under our equity incentive plans and related information is as follows: Options Outstanding Number of Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life (In Years) Aggregate Intrinsic Value (in thousands) Balance as of January 31, 2017 56,840,189 $ 7.15 7.0 $ 315,502 Options granted — — Options exercised (1,340,121 ) 1.84 Options forfeited/cancelled (605,324 ) 12.74 Balance as of April 30, 2017 54,894,744 $ 7.22 6.7 $ 273,338 Vested and exercisable as of April 30, 2017 30,739,000 $ 4.45 6.0 $ 208,957
Summary of Restricted Stock Unit Activity Under 2015 Plan	A summary of the restricted stock unit activity under our 2015 Plan and related information is as follows: Number of Restricted Stock Units Outstanding Weighted- Average Grant Date Fair Value Aggregate Unvested Balance as of January 31, 2017 8,783,024 $ 13.06 $ 99,863 Granted 8,014,950 10.19 — Vested (794,543 ) 10.38 — Forfeited (376,522 ) 12.18 — Unvested Balance as of April 30, 2017 15,626,909 $ 11.74 $ 165,802
Summarizes the Components of Stock-Based Compensation	The following table summarizes the components of stock-based compensation expense recognized in the condensed consolidated statements of operations (in thousands): Three Months Ended 2016 2017 Cost of revenue—product $ 106 $ 397 Cost of revenue—support 1,092 1,774 Research and development 11,658 15,588 Sales and marketing 7,519 10,626 General and administrative 2,623 3,834 Total stock-based compensation expense $ 22,998 $ 32,219

Net Loss per Share Attributab21

Net Loss per Share Attributable to Common Stockholders (Tables)	3 Months Ended
	Apr. 30, 2017
Earnings Per Share [Abstract]
Summary of Computation of Basic and Diluted Net Loss per Share Attributable to Common Stockholders	The following table sets forth the computation of basic and diluted net loss per share attributable to common stockholders (in thousands, except per share data): Three Months Ended 2016 2017 Net loss $ (63,788 ) $ (62,374 ) Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted 189,283 205,783 Net loss per share attributable to common stockholders, basic and diluted $ (0.34 ) $ (0.30 )
Summary of Weighted-average Outstanding Shares Excluded from Computation of Diluted Net Loss per Share Attributable to Common Stockholders	The following weighted-average outstanding shares of common stock equivalents were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods presented because including them would have been anti-dilutive (in thousands): Three Months Ended 2016 2017 Stock options to purchase common stock 68,407 55,895 Restricted stock units 1,375 11,722 Early exercised stock options 2,666 390 Employee stock purchase plan 364 336 Total 72,812 68,343

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Apr. 30, 2017
Segment Reporting [Abstract]
Schedule of Revenue by Geographic Area	The following table sets forth revenue by geographic area based on the billing address of our customers (in thousands): Three Months Ended 2016 2017 United States $ 111,227 $ 146,494 Rest of the world 28,720 36,137 Total revenue $ 139,947 $ 182,631
Schedule of Long-Lived Assets by Geographic Area	Long-lived assets by geographic area are summarized as follows (in thousands): As of As of United States $ 78,692 $ 79,491 Rest of the world 3,003 2,802 Total long-lived assets $ 81,695 $ 82,293

Basis of Presentation and Sum23

Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2017	Apr. 30, 2016	Jan. 31, 2017
Accounting Policies [Abstract]
Restricted cash	$ 12,732		$ 12,734
Deferred commissions, current	16,409		15,787
Deferred income taxes, non-current	14,700		$ 14,900
Sales commission expenses	$ 20,500	$ 17,600

Financial Instruments - Summary

Financial Instruments - Summary of Cash Equivalents, Marketable Securities and Restricted Cash by Significant Investment Categories (Details) - USD ($) $ in Thousands	Apr. 30, 2017	Jan. 31, 2017
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 373,987	$ 376,774
Gross Unrealized Gains	324	268
Gross Unrealized Losses	(769)	(830)
Fair Value	386,274	388,946
Cash Equivalents	6,324	13,226
Marketable Securities	367,218	362,986
Restricted Cash	12,732	12,734
Money market accounts | Level 1
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	0	0
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	12,732	12,734
Cash Equivalents	0	0
Marketable Securities	0	0
Restricted Cash	12,732	12,734
U.S. government treasury notes | Level 2
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	144,028	148,298
Gross Unrealized Gains	26	22
Gross Unrealized Losses	(313)	(289)
Fair Value	143,741	148,031
Cash Equivalents	6,324	13,226
Marketable Securities	137,417	134,805
Restricted Cash	0	0
U.S. government agencies | Level 2
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	41,576	40,398
Gross Unrealized Gains	1	2
Gross Unrealized Losses	(147)	(159)
Fair Value	41,430	40,241
Cash Equivalents	0	0
Marketable Securities	41,430	40,241
Restricted Cash	0	0
Corporate debt securities | Level 2
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	186,005	185,701
Gross Unrealized Gains	295	242
Gross Unrealized Losses	(307)	(379)
Fair Value	185,993	185,564
Cash Equivalents	0	0
Marketable Securities	185,993	185,564
Restricted Cash	0	0
Foreign government bonds | Level 2
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	2,378	2,377
Gross Unrealized Gains	2	2
Gross Unrealized Losses	(2)	(3)
Fair Value	2,378	2,376
Cash Equivalents	0	0
Marketable Securities	2,378	2,376
Restricted Cash	$ 0	$ 0

Financial Instruments - Schedul

Financial Instruments - Schedule of Amortized Cost and Estimated Fair Value of Marketable Securities by Contractual Maturity (Details) $ in Thousands	Apr. 30, 2017USD ($)
Investments, Debt and Equity Securities [Abstract]
Due within one year, Amortized Cost	$ 162,839
Due in one to five years, Amortized Cost	204,824
Total, Amortized Cost	367,663
Due within one year, Fair Value	162,757
Due in one to five years, Fair Value	204,461
Total, Fair Value	$ 367,218

Financial Instruments - Sched26

Financial Instruments - Schedule of Gross Unrealized Losses and Fair Values for Investments that were in Continuous Unrealized Loss Position for Less Than 12 Months, Aggregated by Investments Category (Details) $ in Thousands	Apr. 30, 2017USD ($)
Fair Value
Less than 12 months	$ 245,380
Greater than 12 months	2,269
Total	247,649
Unrealized Loss
Less than 12 months	(763)
Greater than 12 months	(6)
Total	(769)
U.S. government treasury notes
Fair Value
Less than 12 months	120,441
Greater than 12 months	0
Total	120,441
Unrealized Loss
Less than 12 months	(313)
Greater than 12 months	0
Total	(313)
U.S. government agencies
Fair Value
Less than 12 months	38,679
Greater than 12 months	0
Total	38,679
Unrealized Loss
Less than 12 months	(147)
Greater than 12 months	0
Total	(147)
Corporate debt securities
Fair Value
Less than 12 months	85,382
Greater than 12 months	2,269
Total	87,651
Unrealized Loss
Less than 12 months	(301)
Greater than 12 months	(6)
Total	(307)
Foreign government bonds
Fair Value
Less than 12 months	878
Greater than 12 months	0
Total	878
Unrealized Loss
Less than 12 months	(2)
Greater than 12 months	0
Total	$ (2)

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Inventory (Details) - USD ($) $ in Thousands	Apr. 30, 2017	Jan. 31, 2017
Balance Sheet Components Disclosure [Abstract]
Raw materials	$ 10,865	$ 3,003
Finished goods	28,613	20,495
Inventory	$ 39,478	$ 23,498

Balance Sheet Components - Sc28

Balance Sheet Components - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Apr. 30, 2017	Jan. 31, 2017
Property Plant And Equipment [Line Items]
Total property and equipment	$ 190,211	$ 175,302
Less: accumulated depreciation and amortization	(107,918)	(93,607)
Property and equipment, net	82,293	81,695
Test equipment
Property Plant And Equipment [Line Items]
Total property and equipment	116,629	105,955
Computer equipment and software
Property Plant And Equipment [Line Items]
Total property and equipment	57,453	54,521
Furniture and fixtures
Property Plant And Equipment [Line Items]
Total property and equipment	4,691	4,494
Leasehold improvements
Property Plant And Equipment [Line Items]
Total property and equipment	$ 11,438	$ 10,332

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2017	Apr. 30, 2016
Balance Sheet Components Disclosure [Abstract]
Depreciation and amortization	$ 14,400	$ 10,100
Intangible assets amortization expense	$ 376	$ 326

Balance Sheet Components - Sc30

Balance Sheet Components - Schedule of Intangible Assets, Net (Details) - USD ($) $ in Thousands	Apr. 30, 2017	Jan. 31, 2017
Finite Lived Intangible Assets [Line Items]
Intangible assets, net	$ 6,184	$ 6,560
Technology patents
Finite Lived Intangible Assets [Line Items]
Technology patents	10,125	10,125
Accumulated amortization	(3,941)	(3,565)
Intangible assets, net	$ 6,184	$ 6,560

Balance Sheet Components - Sc31

Balance Sheet Components - Schedule of Expected Amortization Expenses for Intangible Assets (Details) - USD ($) $ in Thousands	Apr. 30, 2017	Jan. 31, 2017
Balance Sheet Components Disclosure [Abstract]
Remainder of 2018	$ 1,128
2,019	1,504
2,020	1,504
2,021	1,504
2,022	544
Intangible assets, net	$ 6,184	$ 6,560

Balance Sheet Components - Sc32

Balance Sheet Components - Schedule of Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	Apr. 30, 2017	Jan. 31, 2017
Balance Sheet Components Disclosure [Abstract]
Sales and use tax payable	$ 292	$ 540
Accrued professional fees	1,018	1,765
Accrued marketing	5,041	6,718
Accrued travel and entertainment expenses	3,015	2,235
Income tax payable	1,271	1,135
Other accrued liabilities	5,344	9,304
Total accrued expenses and other liabilities	$ 15,981	$ 21,697

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	Apr. 30, 2017	Jan. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Total operating lease obligations	$ 2
Outstanding letters of credit	$ 7.7	$ 7.7

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details)	Apr. 30, 2017class$ / sharesshares	Jan. 31, 2017$ / sharesshares	Oct. 31, 2015shares
Class Of Stock [Line Items]
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000	20,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Number of classes of stock | class	2
Common stock, shares authorized (in shares)	2,250,000,000	2,250,000,000
Common stock, par value per share (in dollars per share) | $ / shares	$ 0.0001	$ 0.0001
Common stock, shares issued (in shares)	208,119,000	204,364,000
Common stock, shares outstanding (in shares)	208,119,000	204,364,000
Class A
Class Of Stock [Line Items]
Common stock, shares authorized (in shares)	2,000,000,000	2,000,000,000
Common stock, par value per share (in dollars per share) | $ / shares	$ 0.0001	$ 0.0001
Common stock, shares issued (in shares)	93,270,847	87,027,000
Common stock, shares outstanding (in shares)	93,270,847	87,027,000
Class B
Class Of Stock [Line Items]
Common stock, shares authorized (in shares)	250,000,000	250,000,000
Common stock, par value per share (in dollars per share) | $ / shares	$ 0.0001	$ 0.0001
Common stock, shares issued (in shares)	114,848,323	117,337,000
Common stock, shares outstanding (in shares)	114,848,323	117,337,000

Equity Incentive Plans - Additi

Equity Incentive Plans - Additional Information (Details)	Mar. 16, 2016USD ($)	Aug. 31, 2015USD ($)periodshares	Apr. 30, 2017USD ($)planshares	Apr. 30, 2016USD ($)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of equity incentive plans | plan			2
Total stock-based compensation expense			$ 32,219,000	$ 22,998,000
Compensation cost, weighted average term			2 years 8 months
2015 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity awards of vest expire period (no later than)			10 years
2015 Equity Incentive Plan | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Purchase price as percentage of fair market value of common stock			100.00%
Equity awards of vest period			2 years
2015 Equity Incentive Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Equity awards of vest period			4 years
2015 Equity Incentive Plan | Class A
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares initially reserved for issuance (in shares) | shares			27,000,000
Increase in shares reserved by percentage of capital stock			5.00%
2015 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Employee stock purchase plan offering period	24 months
Number of purchase periods | period		4
Purchase period, term		6 months
Modification charge related to the ESPP reset	$ 9,000,000
Total stock-based compensation expense			$ 4,100,000	$ 4,200,000
Unrecognized stock-based compensation expense			$ 27,900,000
Compensation cost, weighted average term			1 year 10 months 24 days
2015 Employee Stock Purchase Plan | Class A
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Increase in shares reserved by percentage of capital stock		1.00%
Purchase price as percentage of fair market value of common stock		85.00%
Shares reserved for future issuance (in shares) | shares		3,500,000
Payroll deductions percentage		30.00%
Share cap for ESPP at purchase date (in shares) | shares		3,000
Calendar year gap for ESPP contribution amount		$ 25,000

Equity Incentive Plans - Stock

Equity Incentive Plans - Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Apr. 30, 2017	Jan. 31, 2017	Apr. 28, 2017
Options Outstanding, Number of Shares
Beginning balance (in shares)	56,840,189
Options granted (in shares)	0
Options exercised (in shares)	(1,340,121)
Options forfeited/cancelled (in shares)	(605,324)
Ending balance (in shares)	54,894,744	56,840,189
Options Outstanding, Number of Shares, Vested and exercisable (in shares)	30,739,000
Options Outstanding, Weighted Average Exercise Price
Beginning balance (in dollars per share)	$ 7.15
Options granted (in dollars per share)	0
Options exercised (in dollars per share)	1.84
Options forfeited/cancelled (in dollars per share)	12.74
Ending balance (in dollars per share)	7.22	$ 7.15
Weighted Average Exercise Price, Vested and exercisable (in dollars per share)	$ 4.45
Weighted- Average Remaining Contractual Life
Weighted Average Remaining Contractual Life	6 years 8 months 12 days	7 years
Weighted Average Remaining Contractual Life, Vested and exercisable	6 years 11 days
Aggregate Intrinsic Value
Aggregate Intrinsic Value	$ 273,338	$ 315,502
Aggregate Intrinsic Value, Vested and exercisable	208,957
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation cost, stock options	$ 115,600
Compensation cost, weighted average term	2 years 8 months
Class A
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Closing price of stock (in dollars per share)			$ 10.61

Equity Incentive Plans - Restri

Equity Incentive Plans - Restricted Stock Units (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Apr. 30, 2017	Apr. 30, 2016	Jan. 31, 2017
Weighted-Average Grant Date Fair Value
Compensation cost, weighted average term	2 years 8 months
Stock-based compensation expense	$ 32,219	$ 22,998
Restricted Stock Units
Number of Restricted Stock Units Outstanding
Unvested, Beginning balance (in shares)	8,783,024
Granted (in shares)	8,014,950
Vested (in shares)	(794,543)
Forfeited (in shares)	(376,522)
Unvested, Ending balance (in shares)	15,626,909
Weighted-Average Grant Date Fair Value
Beginning balance (in dollars per share)	$ 13.06
Granted (in dollars per share)	10.19
Vested (in dollars per share)	10.38
Forfeited (in dollars per share)	12.18
Ending balance (in dollars per share)	$ 11.74
Aggregate Intrinsic Value	$ 165,802		$ 99,863
Compensation not yet recognized	$ 165,300
Compensation cost, weighted average term	2 years 7 months
Performance Shares
Number of Restricted Stock Units Outstanding
Granted (in shares)	827,000
Weighted-Average Grant Date Fair Value
Stock-based compensation expense	$ 468
Performance Shares | Minimum
Number of Restricted Stock Units Outstanding
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	0.00%
Performance Shares | Maximum
Number of Restricted Stock Units Outstanding
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	150.00%

Equity Incentive Plans - Stock-

Equity Incentive Plans - Stock-Based Compensation Expenses (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2017	Apr. 30, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 32,219	$ 22,998
Cost of revenue—product
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	397	106
Cost of revenue—support
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	1,774	1,092
Research and development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	15,588	11,658
Sales and marketing
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	10,626	7,519
General and administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation expense	$ 3,834	$ 2,623

Net Loss per Share Attributab39

Net Loss per Share Attributable to Common Stockholders - Summary of Computation of Basic and Diluted Net Loss per Share Attributable to Common Stockholders (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Apr. 30, 2017	Apr. 30, 2016
Earnings Per Share [Abstract]
Net loss	$ (62,374)	$ (63,788)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted (in shares)	205,783	189,283
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.30)	$ (0.34)

Net Loss per Share Attributab40

Net Loss per Share Attributable to Common Stockholders - Summary of Weighted-average Outstanding Shares Excluded from Computation of Diluted Net Loss per Share Attributable to Common Stockholders (Details) - shares shares in Thousands	3 Months Ended
	Apr. 30, 2017	Apr. 30, 2016
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share, amount (in shares)	68,343	72,812
Stock options to purchase common stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share, amount (in shares)	55,895	68,407
Restricted stock units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share, amount (in shares)	11,722	1,375
Early exercised stock options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share, amount (in shares)	390	2,666
Employee stock purchase plan
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share, amount (in shares)	336	364

Segment Information - Additiona

Segment Information - Additional Information (Details)	3 Months Ended
	Apr. 30, 2017segment
Segment Reporting [Abstract]
Number of business activity	1
Number of reportable segments	1

Segment Information - Schedule

Segment Information - Schedule of Revenue by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 30, 2017	Apr. 30, 2016
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenue	$ 182,631	$ 139,947
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenue	146,494	111,227
Rest of the world
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenue	$ 36,137	$ 28,720

Segment Information - Schedul43

Segment Information - Schedule of Long-Lived Assets by Geographic Area (Details) - USD ($) $ in Thousands	Apr. 30, 2017	Jan. 31, 2017
Revenues From External Customers And Long Lived Assets [Line Items]
Total long-lived assets	$ 82,293	$ 81,695
United States
Revenues From External Customers And Long Lived Assets [Line Items]
Total long-lived assets	79,491	78,692
Rest of the world
Revenues From External Customers And Long Lived Assets [Line Items]
Total long-lived assets	$ 2,802	$ 3,003